2006-12-31 06:36:38 · 5 answers · asked by ♥me 4 eva♥ 2 in Science & Mathematics ➔ Chemistry
it is used to measure H+ ion conc. in a solution.The concept was introduced by S.P.L. Sørensen in 1909, and is purported to mean pondus hydrogenii in Latin. However, most other sources attribute the name to the French term pouvoir hydrogène In English, pH can stand for "hydrogen power,"power of hydrogen,"or "potential of hydrogen. All of these terms are technically correct.
2006-12-31 06:43:06 · answer #1 · answered by rad_g16 2 · 1⤊ 1⤋
pH was originally written by Dr Sørensen as PH, and it stands for pondus hydrogenii which means "potential hydrogen". The terminology refers to acidity being due to a predominance of hydrogen ions in an aqueous (water containing) solution.
In 1909 S.P.L. Sorensen published a paper in Biochem Z in which he discussed the effect of H1+ ions on the activity of enzymes. In the paper he invented the term pH to describe this effect and defined it as the -log[H1+ ]. In 1924 Sorensen realized that the pH of a solution is a function of the "activity" of the H1+ ion not the concentration and published a second paper on the subject. A better definition would be pH=-log[aH1+ ], where aH1+ denotes the activity of the H1+ ion. The activity of an ion is a function of many variables of which concentration is one. It is unfortunate that chemistry texts use a definition for pH that has been obsolete for over 50 years.
Because of the difficulty in accurately measuring the activity of the H1+ ion for most solutions the International Union of Pure and Applied Chemistry (IUPAC) and the National Bureau of Standards (NBS) has defined pH as the reading on a pH meter that has been standardized against standard buffers.
The activity of the H1+ ion is determined as accurately as possible for the standard solutions used. The identity of these solutions vary from one authority to another, but all give the same values of pH to ± 0.005 pH unit.
The historical definition of pH is correct for those solutions that are so dilute and so pure the H1+ ions are not influenced by anything but the solvent molecules (usually water). In most solutions the pH differs from the -log[H1+ ] in the first decimal point.
2006-12-31 14:44:17 · answer #2 · answered by ♥Princess♥ 4 · 0⤊ 1⤋
potential hydrogen. The pH of a substance is as follows:
ph = - log(base 10)[H+]
That is, it is the negative of the base 10 logarithm of the molar concentration (# of moles per liter of solution) of hydrogen ions in the solution.
For example, if you have a 1 molar solution of HCl, you can calculate the pH as follows:
pH = -log(base 10)[H+]
= -log(base 10)(1)
= 0 (very acidic!)
2006-12-31 14:44:03 · answer #3 · answered by Me!!!! 1 · 0⤊ 2⤋
i am not sure about "p" but i know H is hydrogen which it measure the acidity of the soultion or whatever.....
more H+ means more acidic
i hope u.v got ur answer
just to make sure u can check:
http://en.wikipedia.org/wiki/PH
and also happy new year!!
and good attitude for u to creat questions n the middle of the holidays!!!
lol
2006-12-31 14:46:41 · answer #4 · answered by peyman_m89 2 · 0⤊ 1⤋
phosphate
2006-12-31 14:45:44 · answer #5 · answered by PAUL A 4 · 0⤊ 1⤋